luckythirteen13

i run distilled water in my car. its cheap and afr recommends it so why not

MadMan@TheWheel

It is not a bad idea so far as chemistry...but not needed.

r.barn

it has to do with electrolysis.

when you put two different kinds of metals and seperate them by
a fluid that will conduct electricity you have created a battery and it will
corrode away the aluminum as it transfers electrons to the iron.

distilled water has no impurities so it can not conduct electricity and so
prevents corrosion.

Its best to use distilled, but using tap water wont destroy your engine
as long as your good about flushing coolant twice a year.

Can be problem though, I have seen electrolysis eat right thru the side of
a $50,000 Mercedes diesel engine block before, because wrong antifreeze was used.

capri debris

Distilled water is recommended for ALL engines, not because of the type of metal used, but becauseMINERALS are dissolved in tap water. This is the crusty stuff you see around the neck when you take an old hose off. It'll clog your radiator, destroy your water pump bearing and seal. I never use tap water....EVER. For all you guys out there about to come in say they use tap water with no problems...next time you change yourthermostat, let me know if you see tannish/brown crusty stuff in there. Mineral deposits are the #1 cause for sticking thermostats.

ZachW04Stang

That will cause more problems then antifreeze. You motor is iron, and water sitting on iron will cause rust. You will get a lot of rust in you more which could clog coolant ports, get build up at the termistat and on your coolant sensor. Also water has a much lower boiling point. Water boils at 212* so with even a slight over heating water will begin to boil out of your cooling system and create excess pressure. Coolant doesn't boil till around 240 or 250.